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Energy Express

  • Editor: Christian Seassal
  • Vol. 22, Iss. S1 — Jan. 13, 2014
  • pp: A188–A197

Index-matched IWKB method for the measurement of spatially varying refractive index profiles within thin-film photovoltaics

Y. T. Pang, M. Bossart, and M. D. Eisaman  »View Author Affiliations

Optics Express, Vol. 22, Issue S1, pp. A188-A197 (2014)

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In many thin-film photovoltaic devices, the photoactive layer has a spatially varying refractive index in the substrate-normal direction, but measurement of this variation with high spatial resolution is difficult due to the thinness of these layers (typically 200 nm for organic photovoltaics). We demonstrate a new method for reconstructing the depth-dependent refractive-index profile with high spatial resolution (~10 nm at a wavelength of 500 nm) in thin (200 nm) photoactive layers by depositing a relatively thick index-matched layer (1-10 μm) adjacent to the photoactive layer and applying the Inverse Wentzel-Kramers-Brillouin (IWKB) method. This novel technique, which we refer to as index-matched IWKB (IM-IWKB), is applicable to any thin film, including the photoactive layers of a broad range of thin-film photovoltaics.

© 2014 Optical Society of America

OCIS Codes
(040.5350) Detectors : Photovoltaic
(160.4890) Materials : Organic materials
(310.3840) Thin films : Materials and process characterization
(310.6860) Thin films : Thin films, optical properties
(350.6050) Other areas of optics : Solar energy
(310.2785) Thin films : Guided wave applications

ToC Category:

Original Manuscript: November 8, 2013
Revised Manuscript: December 30, 2013
Manuscript Accepted: January 4, 2014
Published: January 13, 2014

Y. T. Pang, M. Bossart, and M. D. Eisaman, "Index-matched IWKB method for the measurement of spatially varying refractive index profiles within thin-film photovoltaics," Opt. Express 22, A188-A197 (2014)

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